In recent years, a method of reading a two-dimensional code printed on a printed material or the like with a mobile phone and a smartphone etc, and downloading a video associated with the two-dimensional code, which has been read, has prevailed (Patent document 1).
However, printing the two-dimensional code on a printed material does not only impair a clear appearance of the printed material, but also requires space for printing the two-dimensional code. Therefore, from the viewpoint of emphasizing the clear appearance of the printed material, or from the viewpoint of efficient use of the printing space, “the smartphone reading system” has been developed using a digital watermarking technology which does not need to print a bar code and the like. As a representative technique of the same, there is a patent application titled “Fast signal detection and distributed computing in mobile computing devices” (Patent document 2).
On the other hand, as a technique for identifying an image using the image information, the AR (Augmented Reality) Technology has also been proposed (Non-patent document 1). In this technique, the image information is read using a smartphone and the like, and then the contour information specific to its image is extracted from the image information, and thus the image is identified. Based on the contour information specific to the image, image related information (hereinafter referred to as “related information”) is searched over the network. The related information obtained by the search is then transmitted to the smartphone or the like with which the image was captured, and will be displayed along with the image information on the screen of the smartphone. In this technique the contour information is extracted by parsing the image information using an image recognition technology.
In addition, as a technology to facilitate the handling of such image information, a technology titled “Image encoding device and method, and its program” related to a method for direct coding of image information has also been proposed (Patent document 3).